Since digital broadcasting launched, people have more and more opportunities to watch and listen to video and audio of higher quality than the video and audio of conventional analog broadcasting. For example, the video of a conventional analog broadcast is presented by interlaced scanning using 525 scan lines, and is called “standard resolution video” or “standard definition (SD) video”. Meanwhile, the video of a digital broadcast is presented by either a similar interlaced scanning technique that uses 1,125 scan lines or a progressive scanning technique that uses 525 scan lines, and its quality is higher than that of the SD video. That is why the video of a digital broadcast is called “high resolution video”, “high quality video” or “high definition (HD) video”. In this description, the video to be presented either by using the greater number of scan lines than the SD video or by the progressive scanning technique will be referred to herein as “HD video”.
Recently, HD video recorders have become increasingly popular among consumers. To record HD video without lowering its quality, a storage medium that can store the HD video as digital data while maintaining a required data transfer rate for reading and writing the HD video is needed. Patent Document No. 1 discloses a recorder/player for recording and playing HD video by using a hard disk as such a storage medium. This recorder/player also has the function of writing data on a normal optical disk, on which only SD video data can be stored, and can dub the video on the hard disk onto such an optical disk.
Patent Document No. 1: Japanese Patent Application Laid-Open Publication No. 2002-330401